New cystic fibrosis drug (Vertex)

Vertex Pharmaceuticals said that a combination of two of its medicines had successfully treated cystic fibrosis in a closely watched clinical trial, paving the way for regulators to approve a new option for sufferers of the deadly genetic illness.

The treatment had fewer side-effects than another drug combination already sold by Vertex, known as Orkambi, which became the first medicine able to treat a large proportion of cystic fibrosis patients when it was approved in 2015.

Sales of Orkambi have significantly underperformed investor expectations because about 15 per cent of eligible patients stopped taking the treatment due to intolerable side-effects such as chest tightening.

This latest combination, which has not yet been named, would offer an alternative to those who cannot tolerate Orkambi’s side-effects, and to newly diagnosed patients, said Steve Rowe, director of the cystic fibrosis research centre at the University of Alabama at Birmingham.

“The efficacy looks very similar, and you lose the problem of ‘bronchospasm’ or chest tightening, which affected 10-15 per cent of patients,” added Dr Rowe.

Orkambi generated revenues of $980m last year, less than half the amount analysts had been forecasting, as doctors stopped prescribing the medicine and experimented with lower doses.

Vertex also struggled to secure reimbursement from cash-strapped European healthcare systems because of the medicine’s $259,000 price tag.

Shares of the biotech group suffered during 2016, losing more than 41 per cent of their value. But the stock has rallied 22 per cent this year in anticipation of data from studies of new experimental medicines.

The company’s shares rose 18 per cent in after-hours trading on Tuesday as investors digested the results of the latest clinical trial, giving Vertex a market capitalisation of more than $27bn.

About 75,000 people worldwide have cystic fibrosis, an inherited disease caused by defects in a gene that controls water and salt levels in cells. The illness leads to a build-up of mucus in the respiratory system, lung damage, and life-threatening infections. Many sufferers die before they are 40.

Vertex won approval for the first drug that slows down the disease, Kalydeco, in 2012, although the medicine only works in a minority of about 4 per cent of patients who have a specific genetic mutation.

The subsequent approval of Orkambi in 2015 provided a treatment option to almost half of people who suffer from the most common “homozygous” form of the disease.

The trial of the latest combination was as good as Orkambi at boosting a patient’s lung function but was also safer. Less than 3 per cent of patients left the trial due to side effects, around the same proportion as those taking the placebo.

Analysts said the biggest opportunity for Vertex would be to add a third drug to the new combo to create a “triplet” medicine, able to treat the roughly 25 per cent of patients who still have no options.

Vertex is trialling several drugs that it believes could become the third agent in such a triplet, and the company is expected to release data from mid-stage trials this year.

Analysts at UBS think a triplet drug that successfully treated these “heterozygous” patients would generate up to $3bn in annual sales for Vertex.

“This combination treatment may provide a promising new option for treating the underlying cause of cystic fibrosis in the future, and brings us increasingly closer to our goal of developing new medicines for all people with the disease,” said Dr Jeffrey Chodakewitz, chief medical officer at Vertex.

Vertex faces competition in the race to develop a drug for untreatable cystic fibrosis patients, chiefly from Galapagos, a Belgo-Dutch biotech group that is developing medicines in collaboration with “big pharma” company AbbVie.

Galapagos is expected to release trial data on its triplet medicine either later this year or at the start of 2018.